2008 U.S. Olympic team member; U.S. Olympic Trials marathon record holder

Hall heads to the games this month as the fastest U.S.-born marathoner ever (2:06:17). To get there, he combines intervals, long-distance runs, weight lifting, and form drills. Each week, he averages 145 miles, including a mile of 50- to 150-meter sprints. “In the marathon, you’re going to get glycogen-depleted, which drains your prime movers—the muscles you use every day,” says Mahon, 37. “When these muscles hit the wall, you need your smaller muscles to take over. The only way they’ll be strong enough to pull through is if you’ve trained them with hard sprint workouts.” Hall also adds speed work to the end of his long runs, capping off a two-hour run with ten one-minute surges. “We end with something fast,” Mahon says, “to force his body to learn to adapt when it’s in a really fatigued state.”

Mahon also takes an active role in tweaking Hall’s form. “We’re not trying to disturb the natural flow of running,” he says, “just trying to improve it a little bit.” To perfect Hall’s stride, Mahon prescribes a series of daily “dribble drills.” He has him start at a walk and then gradually get faster, raising his feet as high as his ankles, then his calves, and finally his knees—simulating ideal form at a jog, at marathon speed, and at a sprint. “Think about a kid on a swing,” Mahon says. “You want to kick your legs out and then pull them back under you as fast as possible.” That momentum propels you forward. “As soon as my foot hits the ground, I focus on getting my heel up to my butt as quickly as I can,” Hall says. “This one movement is what generates speed.”

Finding your ideal footing can be as easy as you want it to be. Frank Shorter, whose gold medal in the 1972 Olympic marathon helped ignite U.S. interest in distance running, has followed an appealingly simple approach: “The more you play around with your stride, the worse it’ll be,” says Shorter, 60, who still logs up to 50 miles a week. “If you want to improve your running form, just do distance intervals.” For Shorter, that means training at a much faster pace than he’ll run on race day: “I trained like a 5K runner for the marathon,” he says. “So I was incredibly relaxed racing at my marathon pace. Your body finds the groove that lets you be most efficient at maximum effort.”

“I don’t want to just float through the water—I want to be a torpedo,” says Hansen, who combines daily swimming workouts of about 12,000 meters with three weekly hour-and-a-half weight lifting sessions. Squats, leg curls, bench presses, and pull-downs are crucial, but more than anything, “a strong core is key,” Hansen says. “It enables you to hold your form in water’s suspended environment.”

The secret to his killer six-pack (and podium-topping pace) is a combo of exercises that works his entire midsection. “Don’t just lie on the mat and do 50 crunches. I do 20 reps each of five different ab moves—like regular crunches, one-minute planks, and toe touches—back-to-back.”

Next: Brett Heyl: Whitewater Slalom

Brett Heyl, 26: Whitewater Slalom

2008 Pan-American Champion; 2004 Olympic team member

Heyl was a competitive ski racer long before he ever picked up a paddle; he plays a lot of soccer, tennis, hockey, and baseball too. Not surprising, then, that he seeks out variety in his workouts. “If I were getting paid a million bucks a year, I would see kayaking as my job,” he says. “But I’m not, so I have to enjoy it. I try to find a balance, to keep my interest, and sometimes that means running and spending more time in the gym and less in the kayak.”

During a race, Heyl says, a bit of self-delusion also comes in handy. “At the end of the course, I’m nearly finished. The long slog’s over. At that point, I can talk myself into stepping it up, since I only have 20 seconds of hard paddling to the finish line. So throughout the race, I just convince myself to go all out for those last 20 seconds—over and over and over again. I try to make my stubbornness work for me.”

Next: Willow Koerber: Mountain Bike Racing

Willow Koerber, 30: Mountain Bike Racing

Top American female in the 2007 World Cup

“The only difference between me and the next guy is how well I master my fear,” says Koerber. “We all train hard, so it really all comes down to your mind. I remind myself that I’m in control of the bike. I’m not a passenger; I’m the driver.”

To keep her training regimen feeling fresh, Koerber bunches her workouts into blocks: “I’ll spend three or four hours on my bike for five days in a row. Then I’ll take the next three days off to recover. I’m a big fan of natural healing: I love spas, massages, and Pilates,” she says. “By the time the break is over, I’m pumped to get back in the saddle. So my heart’s always in it.”